Diagnostic ut ility of the autism diagnostic observat ion schedule in a clinical sample of adolescents and adults

Background The Autism Diagnostic Observation Schedule (ADOS) Module 4 was investigated in an independent clinical sample of highfunctioning adolescent and adult males and females with suspected autism spectrum disorder. Special attention was paid to the performance of the ADOS in the subgroups autism spectrum disorders (ASD), personality disorders and disorders with onset usually occurring in childhood and adolescence. Method The recently revised algorithm and severity scores for Module 4 were used to analyze predictive values compared to the original algorithm in a sample of N = 356, 21% females, age range 12–68 yrs. Results Both algorithms have good sensitivity and specificity, with slightly better results for the revised algorithm. Diagnostic accuracy is lower for females, older individuals, and individuals with personality disorders or higher intellectual abilities. Conclusion The revised algorithm has good utility when used as part of a comprehensive assessment procedure conducted by an experienced examiner and including information on developmental history.